Assuming a viscoelastic material behaves according to a Maxwell model, the relationship between stress and strain is: fraction numerator begin display style sigma with. on top end style over denominator E end fraction plus sigma over eta equals epsilon with. on top. If this material undergoes a step strain change of epsilon equals 0.0075 mm/mm which is fixed sufficiently long, how long does it take until the stress created by the step change relaxes to 2% of its initial value? With E = 23.7 GPa and = 11,101.11 GPa s given and the result expected to be in s.